It's a sign!

Not sure what it is, but it must signify something!

Maybe it's a reminder that, though we are all on the pavement, some of us are looking at stars?

This was spotted on a pavement by Atlantic Quay in Glasgow. I need to explore next time in in the area to see if there are any more.

It was a beautiful sunny day, yet I chose to blip something gray - what does that signify about me?